Steam generating unit



May 7, 1963 w. R. TAGGERT STEAM GENERATING UNIT Filed April 19, 1960 INVENTOR. Zl/ilmer R. Tagger! BY l 9;! oi nay 3,088,444 STEAM GENERATING UNIT Wilmer R. Taggert, Boylston, Mass, assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Filed Apr. 19, 1960, Ser. No. 23,296 1 Claim. (Cl. 122-459) This invention relates to a steam generating unit and more particularly to apparatus arranged to purify the steam produced by a boiler.

In the generation of steam, it is the usual practice to provide means for purifying the steam before it is passed into the superheater. For that purpose, certain steam treating apparatus has been placed in the path of the steam as it passes through the steam-and Water drum. One of the principal pieces of apparatus for this purpose is the steam condenser, an effective type of which is shown in the patent to Andrews No. 2,424,212, issued July 22, 1947. After the steam has passed over the condenser, it is common practice to pass it over drier cartons which further serve to remove water from the steam. In steam purifying apparatus of this kind, one of the problems most often encountered is that of the removal of condensed or trapped water. Drains have been provided for these devices, but quite often the drains do not operate effectively to remove the water. These and other difliculties experienced with prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of this invention to provide a steam generating unit having a steam purifying apparatus in which accumulated condensed or trapped water is readily removed.

Another object of this invention is the provision of means associated with a steam drier carton for removing accumulated water therefrom.

A further object of the present invention is the provision of a steam generating unit in which the energy of the feed water is used to remove water from the steam purfying apparatus.

It is another object of the instant invention to provide a drainage apparatus for drum internals which is rugged and simple in construction and which will not be rendered ineffective by chemical deposits and extreme temperatures.

With these and other objects in View, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claim appended hereto.

The character of the invention, however, may be best understood by reference to certain of its structural forms, as illustrated by the accompanying drawings in which:

FIG. 1 is a vertical sectional view of a steam generating unit taken on the line II of FIG. 2;

FIG. 2 is a sectional view of a steam generating unit taken on the line II-II of FIG. 1; and

FIG. 3 is a somewhat enlarged sectional view of a portion of the apparatus.

The steam generating unit, indicated generally by the reference numeral is shown as comprising a steamand-water drum 11 having a large downcomer tube 12 at one end and a body 13 of water lying therein. In the upper part of the steam-and water drum are connected steam release tubes 14 and in the uppermost portion are located steam outlet tubes 15. A centrally located generally-vertical baffle 16 and a generally-horizontal baflie 17 located in the upper part of the drum serve to define a steam passage 18 from the steam. release tubes 14 to the steam outlet tubes Located in the lower part of the passage 18 just above the level of the body of water 13 is a series of condensers 19 connected to a feed water States Patent pipe 21. Also located in the passage 18 above the condensers 19 are a series of drier cartons 22 having collector troughs 23 underlying them. The lowermost portion of each of these tubes is connected by a pipe 24 to a drain manifold 25. One end of this pipe is connected through a vertical pipe 26 and a horizontal pipe 27 to an aspirator 28. The outlet of the aspirator is connected to a pipe 29 extending into the downcomer valve and having a flared end 31 lying in the downcomer. Each of the series of condensers 19 is provided with a vertical outlet pipe 32 lying in the body of water '13 and each of these outlet pipes is provided with a nozzle 33 which is directed toward the downcomer tube 12. It will be understood that all of these nozzles on one end of the steam-andwater drum 11 are directed toward the downcomer on its respective one end, while the nozzles located in the other end of the steam-and water drum will be directed toward the downcomer tube at the said other end. The last condenser 19 in the series adjacent the end of the steam-and-water drum is, however, connected through a pipe 34 to a nozzle 35 located in the aspirator 28. As is evident in FIG. 3, the aspiraor 28 is a elbow connected at one side to the pipe 26 and at the other side to the pipe 29. At the bend of the elbow, however, the fitting is provided with the nozzle 35, which is connected to the pipe 34, the nozzle 35 being aligned with the pipe 29.

The operation of the invention will now be readily understood in view of the above discussion. Steam generated in the steam generating unit enters the steam-andwater drum 11 through the steam release tubes 14. It passes through the passage 18 between the bafiles 16 and 17. It passes over the condensers 19 where a certain amount of the steam is condensed and a great many of the impurities are caught in the condensate lying on the plates of the condenser. The steam continues through the drier cartons 22 and passes over the steam-and-water drum through the steam outlet tube 15; then the steam passes to the superheater in the usual manner. Water and foreign matter which is caught in the bafiles of the drier cartons 22 flows downwardly along the drier carton elements into the troughs 23. A considerable amount of this material accumulates in the troughs and it is necessary to remove this rather rapidly for various reasons. First of all, if the troughs overflow, the water is brought back into contact with the steam and the steam is likely to pick up water and carry it over into the steam outlet tubes. Even if the troughs 23 are full but do not over flow, they still present a problem of pick-up by the flowing steam. The feed water, of course, enters the steam-andwater drum through the feed water pipe 21 and passes through each of the condensers taking part in heat exchange with the steam passing over the condensers. In most cases this feed water leaves the pipes 32 through the nozzles 33 and helps to direct the flow of feed water toward the downcomer tube 12. The main flow of water down the downcomer tube 12, of course, takes place due to boiler circulation. The nozzles, however, help to maintain the level of the water in the body of water 13 or approximately the same height throughout the :steam-and-water drum and helps reduce the gradient which would exist because of the flow of water between the center of the steam-and-water drum and the ends. This gradient is a handicap to proper steam treatment because, when a gradient exists, various amounts of the condensers 19 are taking active participation in the steam purification. The feed water, however, flowing through the tube 34 passes through the nozzle 35 in the aspirator 28. This produces an ejector effect on the water in the pipe 26 and adds considerable energy to the water passing through the tube 29. The flow of water down the downcorner tube 12 also acts on the flared end of the pipe 29 and produces a further ejector section tending to cause the water to flow through the tubes. The combination of the ejector action produced by the nozzle 35 and by the flared end 31 causes the water to flow rapidly from the troughs 23 down the pipes 24 into the drain manifold 25; from there it flows through the pipe 26, the aspirator 28, and the pipe 29 into the flow of water through the downcomer.

It will be understood, of course, that the nozzles 33 on the ends of the pipes 32 act as orifices in that they restrict the flow of water through the pipes 32 and permit a suflicient quantity of water to flow through the pipe 34 to produce adequate ejection in the aspirator 28. This arrangement of orifices is necessary to acquire sufficient velocity in the nozzle 35 to accomplish the function desired.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is: 25

A steam generating unit, comprising a steam-and-water drum adapted to contain a body of water, steam release tubes entering the drum, a steam outlet tube leaving the drum, a downcomer tube leaving a lower part of the drum, a passage leading from the steam release tubes to the steam outlet tube, a feed water pipe entering the steam-and-Water drum, a series of condensers connected to the feed water pipe and lying in the said passage for treating steam passing thereover, a series of steam drying devices lying in the passage between the condensers and the steam outlet tube, a feed water supply entering the drum through the feed water pipe and through the condensers, a trough underlying the steam drying devices, a closed tubular conduit extending downwardly from the trough to remove water therefrom, an aspirator in the conduit, at least one of the condensers being connected to the aspirator to cause a portion of the feed water to pass through the aspirator, the other condensers discharging directly into the body of water, and means forming a restriction in each of the said other condensers for controlling the flow of feed water therethrough into the body of water and for producing adequate ejection in the aspirator.

References Cited in the file of this patent UNITED STATES PATENTS 2,055,781 Angermueller Sept. 29, 1936 2,832,322 Taggert Apr. 29, 1958 2,954,014 Rehm Sept. 27, 1960 FOREIGN PATENTS 570,700 Great Britain July 18, 1945 

